Watering systems

ABSTRACT

A method of underground watering utilizes a pouch-like container product made by joining a first sheet having SAP particles adhered to a first surface with a second sheet to form a container partially filled with such particles. The application of pressure, for example by passing the product through a roll nip, facilitates joining of the sheets and causes the particles to break through at least the one of the sheets to create an opening whereby free volume is created to permit the particles to expand when in contact with a liquid. The resultant product is used to collect, store, and dispense water-containing liquids into the soil for watering of agricultural plants, trees, and the like. A composite underground watering element is also included in an embodiment of the invention. The inventive products may also be used as a pad, including a propagation pad, to collect, store, and dispense water-containing-liquids into plant vessels to provide watering of plants. Also included are underground watering of athletic fields and golf course greens, erosion control products and plant root balls having a watering collar.

This application is a continuation-in-part of patent application Ser.No. 11/605,167, filed Nov. 28, 2006, entitled Improved Absorbent Productand Method of Making. Said patent application Ser. No. 11/605,167 waspublished on May 27, 2008 as Publication No. 2008/0125734.

The present invention relates to liquid absorbent products and methodsfor making such products. The invention may be used as a core elementfor absorbent products, such as diapers, training pants, feminine careproducts, and the like or as a water collection, storage, and dispensingelement for applications such as irrigation, erosion control, or plantwatering and plant root growth control.

BACKGROUND OF THE INVENTION

Disposable absorbent products currently find widespread use in manyapplications. For example, in the infant and childcare areas, diapersand training pants have generally replaced reusable cloth absorbentarticles. Other typical disposable absorbent products include femininecare products such as sanitary napkins, panty shields, or tampons; adultincontinence products; and health care products such as surgical drapesor wound dressings. A typical disposable absorbent product generallycomprises a composite structure including a top sheet, a back sheet, andan absorbent core structure between the top sheet and back sheet. Theseproducts usually include some type of fastening system for fitting theproduct onto the wearer.

The use of water-swellable, generally water-insoluble absorbentmaterials, commonly known as superabsorbent polymers (“SAP”), indisposable absorbent personal care products is known. Such absorbentmaterials are generally employed in absorbent products in order toincrease the absorbent capacity of such products while reducing theiroverall bulk. Such absorbent materials are generally present inabsorbent products in the form of small particles and may be included ina fibrous matrix, such as a matrix of wood pulp fluff. A matrix of woodpulp fluff generally has an absorbent capacity of about 6 grams ofliquid per gram of fluff. The superabsorbent materials generally have anabsorbent capacity of at least about 10, preferably of about 20, andoften of up to 100 times, and even up to 300 times, their weight inwater. Clearly, incorporation of such superabsorbent materials indisposable absorbent products can reduce the overall bulk whileincreasing the absorbent rate and capacity of such products.

The absorbent products mentioned above, such as baby diapers, adultincontinence devices, and feminine hygiene products, may be made with acellulose fiber fluff-based absorbent core sandwiched between a liquidpervious top sheet, which allows the unobstructed passage of fluid tothe absorbent core, and a liquid impervious backing sheet usually ofplastic material, which contains the absorbed fluid and prevents it frompassing through the absorbent core and soiling the undergarments orclothing of the wearer of the absorbent article. The core product of thepresent invention does not require, but may contain, fibrous material.In various embodiments of the present invention, SAP powder is heldwithin a container, with or without fibrous material. The container mayoptionally include openings on either of its surfaces that arepre-formed and/or formed during manufacture so as to admit liquids tobecome absorbed by the SAP powder or even to become collected in liquidform. As will be disclosed in more detail later, the openings createdduring manufacture of the absorbent product by the SAP particles duringthe pressing step are sufficient for most applications.

In recent years, market demand for thinner and more comfortableabsorbent articles has increased. Ultra-thin feminine napkins are nolonger constructed from loose wood pulp, which tends to give a bulkyproduct, but with a roll wood-based air-laid absorbent cores in which aroll or coil of pre-formed absorbent core material is unwound directlyonto the absorbent pad-making machine without the defiberization steprequired for fluff-based products. The roll wood-based approach resultsin a product thinness, which cannot be achieved by loose fluff-basedtechnology. As will be seen later, the present invention can producethinner absorbent products that have comparable or improved absorbencyproperties to thicker products. The present invention thus serves tofurther reduce product thickness and weight.

Although a given SAP particle has the capability to absorb and contain aliquid, in actual practice it is difficult to efficiently utilize thiscapability. If the SAP particles are located as a mass in closeproximity to each other, the rate of absorption and the capacity toretain absorbed liquid are reduced because the liquid will not be ableto reach, or only slowly reach, the interior of the SAP mass. As theouter surface area of the SAP mass begins to absorb liquid, in effect, abarrier is created that substantially slows the rate of liquidabsorption. Consequently, it is understood that the separation, as wellas the size, of the SAP particles are important considerations. Attemptsto address this problem have included adhering the SAP particles tonon-SAP material by hot melt adhesion or the use of resinous binders,including both thermoplastic and thermosetting types. There are problemsassociated with these attempts. The use of such adhering materialscauses encapsulation or partial encapsulation of the SAP particles andthereby prevents or reduces the surface area available for efficientliquid absorption. In addition, free volume for particle expansion iscompromised. Furthermore, even when the SAP particles are initiallyadhered, as the particles expand and soften during the absorption phase,the particles tend to separate and migrate toward other SAP particlesthereby further reducing liquid absorption and free volume. The aboveprior art problems are beneficially addressed by the free volumeconsiderations underlying the present invention.

In any event, many products for absorbing liquids and processes formaking thereof are described in the art. Typical of such products andprocesses are those described in Assignee's co-pending U.S. patentapplication Ser. No. 10/357,907, filed Feb. 4, 2003, and published onSep. 18, 2003, under Publication No. US-2003-0175418-A1; U.S. Pat. No.5,792,513; U.S. Pat. No. 6,485,813; U.S. Pat. No. 5,611,885; and U.S.Pat. No. 6,534,572. However, none of these patents or patentpublications is believed to possess or teach the unique combination ofadvantages of the present invention.

In general, the absorbent product of the present invention may utilizeSAP particles having a predominant amount of particles on the order of amaximum average particle size of about 500 microns and a minimum averageparticle size of about 100 microns and thereby more rapidly absorbliquids, such as water, body fluids, urine, blood, etc., than possiblewhen using coarser particles of the same weight. However, it should beunderstood that lower sized particles may be mixed with larger sizedparticles to further increase the rate of liquid absorption. Suchincreased rapidity of absorption is due to the larger total surface areaof the fine particles. Rapid absorption is particularly important whenthe absorbent product is a portion, such as a core, of a diaper productor the like. The present invention also involves spacing absorbent SAPparticles apart from each other and provides the necessary free volumesurrounding the particles to permit the particles to expand more readilyduring absorption of a liquid to improve absorption capacity, rate, andefficiency and thereby permitting the use of less SAP particles than ifsuch SAP particles were not extended through the sheet surface(s) andnot so spaced apart and did thus not have as much free volume into whichto expand. Creating and maintaining free volume also has the advantageof providing a space to collect and store liquids, such as water, forsubsequent dispensing to, for example, plant root systems. Otherprocesses involving adhering SAP particles to substrates have thedistinct disadvantage of covering, or even encapsulating, a surfaceportion of the SAP particles, thereby reducing the effectiveness of theSAP particles.

While the present invention is primarily described in connection withdiaper products, it will be understood by those skilled in the art thatthe product of the invention may be used in water collection, storage,and dispensing applications including irrigation, erosion control, andfor plant watering and plant root growth control

SUMMARY OF THE INVENTION

The present invention pertains to a method of making an absorbentproduct and the resultant product of such method. The method generallycomprises providing a first sheet, preferably having an adhesive coatedon a first side surface, and a second side surface that is opposed tothe first side surface. Particles of SAP are then applied to the firstsurface. The SAP particles are substantially spaced apart from eachother so as to create free volume for sideways expansion. A surface of asecond sheet is then placed against the coated surface of the firstsheet to join the sheets and to form a product that is partially filledwith the particles. Pressure is applied to the thus arrayed first andsecond sheets to cause the particles to break through the surface of oneor both of the sheets thereby forming an opening and creating freevolume for the particles to expand into when in contact with a liquid.

One product of the invention generally comprises a first sheet having afirst side preferably coated with an adhesive and having particles ofSAP adhered to the first surface. A second sheet is joined to thesurface of the first sheet to form a container being partially filledwith the particles. The particles are substantially spaced apart fromeach other and extend through openings created in one or both of thesheet surfaces thereby creating free volume for the particles to expandinto when in contact with a liquid. The particles may also extendthrough the other sheet to further enhance absorbency of the liquid.

A second product of the invention generally comprises a first sheethaving a first side preferably coated with an adhesive and havingnon-SAP particles adhered to the first surface. A second sheet is joinedto the surface of the first sheet to form a container being partiallyfilled with SAP material such as particles or a film, chips, or films.The non-SAP particles are substantially spaced apart from each other andextend through openings created in one or both of the sheet surfacesthereby creating free volume to permit the SAP material to expand whenin contact with a liquid. This product is especially adapted for longterm use applications such as in irrigation, erosion control, plant rootball watering, and plant root direction control.

A third product of the invention comprises first and second sheetsjoined together to form a container being partially filled with SAPmaterial such as particles, chips, or films. One or both sheets haveopenings to permit the entry and exit of a liquid, such as water. Thisproduct is especially adapted for applications such as those describedin the preceding paragraph.

The present invention also includes a method of underground wateringwherein a liquid containing water is collected, stored, and dispensedinto soil at an underground location. Such method comprises placing acontainer underground in the soil. Such container is partially filledwith particles of SAP. Partial filling creates free volume in thecontainer for the SAP particles to expand into when in contact with aliquid. The liquid comprises water and may contain other ingredientssuch as nutrients for plant nutrition. The container comprising a firstfilm joined with a second film. The first film has an adhesive coatedfirst side surface located on an inside surface of the container and anopposed second side surface located on an outside surface of thecontainer. The second film has a first side surface located on an insidesurface of the container and an opposed second side surface located onan outside surface of the container. The first film is sufficientlybrittle for the particles of SAP to penetrate and break through thefirst film. The SAP particles of superabsorbent polymeric powder are ofsufficiently large size to penetrate and break through the first andsecond side surfaces of the first film. The SAP particles are adhered toand extend through the first and second side surfaces of the first filmthrough an opening created by such penetration and breaking through thefirst film by the SAP particles thereby creating further free volume forthese particles to expand into when in contact with a liquid. The brokenthrough particles are spaced apart from each other to minimize touchingof the broken through particles thereby enhancing liquid absorption rateand creating further free volume for the broken through particles toexpand into when in contact with a liquid. The SAP particles in thecontainer are then contacted with a liquid to cause the particles tocollect and store said liquid. Then later the collected and storedliquid is dispensed into the soil as the soil dries.

The above method may also be practiced where a liquid, such as water, isplaced in the container by 1) permitting water to enter the containerthrough contact with the SAP particles; or 2) introducing water into thecontainer interior from an outside source through an opening. Witheither of these two embodiments, the SAP particles in the containerserve to collect, store, and dispense water into the soil as the soildries.

A further method of underground watering comprises a method ofcollecting, storing, and dispensing water into soil at an undergroundlocation. Such method comprises placing a watering unit containerunderground in the soil. The container is formed by joining a first andsecond film and is partially filled with particles of SAP. The containermay positioned, such as by cladding, upon an exterior surface of ahollow element having openings extending from an interior surface to anexterior surface of the element or the container may be inserted andpositioned or located within the interior of the element. The containermay be attached to the interior of the hollow element if desired toensure positioning is maintained and the SAP particles have access tothe sol through the openings in the hollow element. Interior positioninghas the advantage of being able to be withdrawn and replaced if need be.The element is sealed at one end and connected to a source of liquid,such as water, at the other end. A different watering unit container maybe used as discussed later in the specification. The SAP particles inthe container are free to expand in the container when in contact withthe liquid due to free volume created by partially filling thecontainer. As noted above, the container comprises a first film joinedwith a second film. The films may be made from plastic. The first filmhas an adhesive coated first side surface located on an inside surfaceof the container and an opposed second side surface located on anoutside surface of the container. The second film has a first sidesurface located on an inside surface of the container and an opposedsecond side surface located on an outside surface of the container. Boththe first and second films are sufficiently brittle for said particlesof SAP to penetrate and break through the first and second films. TheSAP particles are of a sufficiently large size to penetrate and breakthrough the first and second side surfaces of the first and second filmsand to extend through the first and second side surfaces of said firstand second films through openings created by penetration and breakingthrough the first and second films by such particles, thereby creatingfurther free volume for said particles to expand into, thereby enhancingthe liquid absorption rate and creating further free volume for saidbroken through particles to expand into when in contact with the liquid.The broken-through particles are spaced apart from each other tominimize touching of such broken-through particles. A liquid, such aswater or water containing plant nutrients or other ingredients, ispassed from the liquid source into the interior of the hollow element tocause such liquid to enter the interior and pass through openings in thesides of the element and then contact the SAP particles in the containerto collect and store such introduced liquid Then the collected andstored liquid is dispensed into the soil as the soil dries. Additionalliquid may be required periodically to compensate for water loss duringdrying of the soil.

The invention also includes an underground composite watering elementproduct for collecting, storing, and dispensing liquids containing waterinto soil. The composite product comprises at least two containers thatare a first film joined with a second film, the first film has anadhesive coated first side surface located on an inside surface of eachcontainer and an opposed second side surface located on an outsidesurface of each container and a second film having a first side surfacelocated on an inside surface of each container and an opposed secondside surface located on an outside surface of each container, the firstfilm is sufficiently brittle for particles of superabsorbent polymericpowder to penetrate and break through the first film. The first film hasSAP particles of sufficiently large size to penetrate and break throughthe first and second side surfaces of the first film. The particles areadhered to and extend through the first and second side surfaces of thefirst film through an opening created by penetration and breakingthrough the first film by the particles thereby creating further freevolume for the particles to expand into when in contact with thewater-containing liquid. The broken through particles are spaced apartfrom each other to minimize touching of such particles thereby enhancingwater absorption rate and creating further free volume for these brokenthrough particles to expand into when in contact with said liquidcontaining water. The SAP particles having broken through the first filmpenetrate the thus created porous covering and extend into the soil. Thecontainers have a water absorbent member interposed between thecontainers to form a composite product. The underground watering elementis connected to a source of water-containing liquid.

A method of watering a plant located in soil may utilize theabove-mentioned composite watering element product. This methodembodiment comprises placing such composite product in soil at alocation below a plant and then providing a water-containing liquid tothe watering element for collecting, storing, and dispensing thewater-containing liquid to the soil to provide water to the plant. Thismethod may be advantageously employed for watering athletic fields andgolf course greens.

The products of the invention may be utilized to control erosion of soilfrom slopes and the like. The product comprising two joined togethersheets or films forming a container having SAP particles extendingthrough at least one of the sheets or films may be placed below the soiland used to collect and store water that otherwise would cause soilerosion through the SAP Particles. Once the water problem has abated,the collected and stored water will then be slowly released back intothe soil through the SAP particles. Collection capability may beenhanced by obtaining further water storage capability by including awater absorbent material between the sheets or films. A preferredmaterial comprises starch containing SAP particles which typically havevery large storage capability. Also contemplated as a water absorbentmaterial is Terra-Sorb®, a potassium acrylamide copolymer. Terra-Sorbproducts are available from Lebanon Turf, Lebanon, Pa. Felt, non-wovenfabrics, compressed fibers, or the like may also be used as a waterabsorbent material.

A further method of erosion control comprises placing underground theabove described underground composite watering element and using sucherosion control element to collect and store water thereby preventingthe collected water from eroding the soil. A further advantageassociated with this method is that plants located in potential erosionareas will be watered by the watering element, grow, and thus serve tofurther prevent erosion.

Another method of erosion control involves placing an erosion controlblanket on ground where erosion is desired to be reduced. The blanketcomprises a watering element and a seeding mat disposed above suchelement. This method comprises placing the blanket on the ground wherebywatering element of the blanket collects, stores, and dispenses water tothe seeding mat to assist the seeds to mature into a plant, such asgrass or shrubs, and then to assist further health of the plants. Thegrowth and subsequent health of the plant serves to reduce undesirableerosion of the ground.

Another product useful in practicing the present invention is a vesselfor holding a plant comprising a container capable of holding a plant,said container having a pad located at a bottom portion of saidcontainer and connected to a source of a water-containing liquid, saidpad comprising a first film joined with a second film, the first filmhaving an adhesive coated first side surface located on an insidesurface of the container and an opposed second side surface located onan outside surface of the container and the second film having a firstside surface located on an inside surface of the container and anopposed second side surface located on an outside surface of thecontainer, the first and second films being sufficiently brittle for SAPparticles to penetrate and break through the first and second films, theSAP particles of sufficiently large size to penetrate and break throughthe first and second side surfaces of the first and second films, theparticles extending through said first and second side surfaces of saidfirst and second films through openings created by penetration andbreaking through the first and second films by the particles therebycreating further free volume for the particles to expand into therebyenhancing liquid absorption rate and creating further free volume forthe broken through particles to expand into when in contact with theliquid, the broken-through particles spaced apart from each other tominimize touching of the other broken through particles. A liquidcontaining water is introduced from below the pad to cause the water tobecome absorbed and collected by the broken-through particles whichextend into the soil and then dispense the stored water from thecontainer to cause watering of plant roots contained in the soil.

The above vessel may also have the broken through SAP particles extendonly in a given direction into the soil. This embodiment requires thatwater be introduced into an interior portion of the pad because the sideopposite to the broken through SAP particle has no such openings.

Another product comprises a plant root ball, such as a tree root ball.The plant has roots and is contained in a soil ball. The root ball iswrapped in a porous covering and has a watering collar secured theretoat a desired location. The watering collar comprises a first film joinedwith a second film. The first film has an adhesive coated first sidesurface located on an inside surface of the water collar container andan opposed second side surface located on an outside surface of thecontainer. The second film has a first side surface located on an insidesurface of the container and an opposed second side surface located onan outside surface of the container. The first film is sufficientlybrittle for the SAP particles to penetrate and break through the firstfilm which has SAP particles of of sufficiently large size to penetrateand break through the first and second side surfaces of the first film.These particles are adhered to and extend through the first and secondside surfaces of the first film through openings created by penetrationand breaking through the first film by the particles thereby creatingfurther free volume for the particles to expand into when in contactwith water. The broken-through particles are spaced apart from eachother to minimize touching of the other broken through particles therebyenhancing water absorption rate and creating further free volume for thebroken through particles to expand into when in contact with water. TheSAP particles, having broken through the first film, then penetrate intothe porous covering and extend into the soil. The watering collar has anopening for connection to a source of liquid whereby the water may beintroduced into an open area in the water collar, collected and storedby the SAP particles, and dispensed into the soil of the plant rootball. Two embodiments of watering collars are described in more detailin a later portion of the specification.

Another embodiment of the present invention concerns a method ofwatering a plant root ball once the root ball has been transplanted intothe soil. Such method comprises placing a watering element containingSAP into an underground opening suitable for holding a plant root ball,and then placing the root ball into the opening, and then providing aliquid containing water into the watering element where the providedliquid passes into the soil whereby the roots of the plant are watered.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of a vertical cross section taken along alongitudinal axis of a product of the invention.

FIG. 2 is an illustration of a vertical cross section taken along alongitudinal axis of a watering element product of the invention shownin combination with a water intake element.

FIG. 3 is an illustration of a vertical cross section taken along alongitudinal axis of a vessel for holding plants in which water isintroduced into the interior of a watering pad or propagation mat.

FIG. 4 is an illustration of a vertical cross section taken along alongitudinal axis of a vessel for holding plants shown in combinationwith a watering pad or propagation mat in which water is introducedexternally into such pad or mat.

FIG. 5 is an illustration of a horizontal cross section of wateringcollar to be placed and secured upon a plant root ball, such as a treeroot ball.

FIG. 6 is an illustration of another horizontal cross section wateringcollar embodiment to be placed and secured to a plant root ball.

FIG. 7 is an illustration of a vertical cross section of an undergroundcomposite watering product.

FIG. 8 is an illustration of a vertical cross section of a golf coursegreen containing the composite product of FIG. 7.

FIG. 9 is an illustration of a vertical cross section of a watering unitutilizing a hollow element having a sheath clad on its exterior surface.

FIG. 10 is an illustration of a vertical cross section of a wateringunit utilizing a hollow element having a sheath inserted into the insideof the hollow element.

DETAILED DESCRIPTION OF THE INVENTION

The products of the present invention are suited for use as cores indisposable products including disposable absorbent products such asdiapers, diaper liners, training pants, wraps and covers, adultincontinence products, and bed pads; incontinence devices; femininehygiene products such as sanitary napkins, panty shields, or tampons;other absorbent products such as wipes, bibs, wound dressings andsurgical capes or drapes, mattress covers and puddle pads. Accordingly,in another aspect, the present invention relates to a disposableabsorbent product utilizing the absorbent core of the present inventionas a component. For example, such product could be used alone or incombination with other absorbent materials in previously-describedabsorbent products such as diapers, feminine hygiene products, adultincontinence products, wiping sheets, surgical drapes, etc. An importantaspect of using this product for absorbent product applications is thatthe size and weight of the absorbent product would be reduced, therebyconferring benefits of comfort and appearance to the user and alsocreating less solid waste per unit. This latter advantage is animportant factor for waste disposal sites. Some absorbent productscontain an acquisition layer to absorb and then more slowly disperseurine or other liquid into a superabsorbent polymeric powder-containingportion of the absorbent product. In accordance with this invention, theuse of fine superabsorbent polymeric powder with its attendant rapidabsorption rates may reduce the size of, or eliminate the need for, suchacquisition layer.

The products of the present invention are also suited to be used assecured elements or containers having sufficient free volume to enhancethe collection, storing, and dispensing of water for irrigationapplications. Simply placing SAP particles in the ground does notaddress or provide the requisite free volume and thus the potentialabsorption properties of such SAP particles are not efficientlyrealized. The elements are placed underground and preferably secured ata desired location(s). Placement may be accomplished by digging a holein the ground, placing and securing the element in such hole, andcovering the element. Alternatively, the element may be placed into theground, for example, by insertion by pushing hollow tube-like members orcomposite strips that contain the element into the ground. The elementmay be adhered to the interior of the tubular member or contained in themember as a strip, wrapped spiral, oval, cylinder, triangle, or thelike. The tubular member preferably may have sidewall openings to permitwater ingress and egress. The tubular member may comprise a rigidmaterial such as metal, plastic, wood, etc. However, a pouch-like fabriccontainer made from, for example, burlap is also suitable for someapplications. The tubular member may be of any desired shape and mayinclude, for example, a half circle or angular member. Such arrangementserves to locate and secure the element at a desired undergroundlocation. Once placed and secured underground, the element functions tocollect, store, and ultimately dispense water for soil irrigation. Thoseskilled in the art will understand that such system may collect andstore rainwater and/or artificially applied water and then dispense suchwater at a later time for watering purposes as the watered soil dries.Securing the placed element at a desired underground location may beaccomplished by affixing or securing the element to a stable element sothat the placed element remains at the desired location and does notmove to a less desired and less effective location.

As may be appreciated by those skilled in the art, the above-mentionedfirst underground watering method embodiment functions by receivingwater from the outside of the container. Such received water is absorbedby the SAP particles and then passes into the interior of the containerthrough the adhered and affixed SAP particles where the water iscollected and stored. Then the stored and collected water may besubsequently passed back to the outside of the device and into the soilas the water content of the soil may dictate as the soil becomes drier.FIG. 1 is an illustration of a vertical cross section taken along alongitudinal axis of a product of the invention useful in practicingthis first method.

In contrast to the above first method, the second method introduceswater to the area between the first and second films where the water iscollected by the SAP particles and then dispensed into the soil. FIG. 2is an illustration of a vertical cross section taken along alongitudinal axis of a product of the invention shown in combinationwith a water intake element. This product is useful in practicing thesecond method.

The second underground watering method embodiment can be broadlysummarized as providing a hollow element having an interior opening,holes through its surface, and associated with a container havingparticles of SAP. The container may be clad upon the exterior surface ofthe hollow element or inserted and located within the hollow element.Locating the container inside of the hollow element is advantageous inthat removal of an old container and replacement thereof is facilitatedwhen the container is so located or associated with the hollow element.The container may be attached or affixed to the interior of the hollowelement if desired to ensure positioning is maintained and the SAPparticles have access to the sol through the openings in the hollowelement. Attachment may be accomplished by spot adhesion or bymechanical means. The element is sealed at one end and connected to asource of liquid, such as water, at the other end. Another embodiment ofthe second underground watering embodiment comprises a compositewatering element which is described in detail at a later portion of thepresent application.

As will become more apparent later, the first underground wateringembodiment may be described as a passive system or method and the secondunderground watering embodiment as an active system or method. Thisdistinction is made because the first embodiment, once locatedunderground, functions by itself by collecting, storing, and dispensingwater. On the other hand, the second embodiment requires an independentsource of water input to function in its intended manner.

The container mentioned in the preceding paragraph is comprised of twofilms joined together and having SAP particles that have penetratedthrough both films and are secured to such films. The hollow element isconnected to a water source. The process requires introducing water,optionally containing nutrients, into the interior of the hollowelement, passing water through openings in the element where such wateris absorbed by SAP particles in the container and then expelled ordispensed into the soil. However, a different watering unit containermay be used such as those discussed later in the specification.

This above method of underground watering collecting, storing, anddispensing water into soil is conducted by placing a containerunderground in soil. The container is formed by joining a first andsecond film and is partially filled with particles of SAP which arebroken through the outer surfaces of both films. The container is cladupon the exterior surface of a hollow element having openings extendingfrom an interior surface to an exterior surface of such element. Theelement is connected to a source of liquid, such as water. The SAPparticles held inside the container are free to expand in the containerwhen in contact with the liquid due to free volume created by partiallyfilling the container. As noted above, the container comprises a firstfilm joined with a second film. The films may be made from plastic. Thefirst film has an adhesive coated first side surface located on aninside surface of the container and an opposed second side surfacelocated on an outside surface of the container. The second film has afirst side surface located on an inside surface of the container and anopposed second side surface located on an outside surface of thecontainer. Both the first and second films are sufficiently brittle forsaid particles of SAP to penetrate and break through the first andsecond films. The SAP particles are of a sufficiently large size topenetrate and break through the first and second side surfaces of thefirst and second films and to extend through the first and second sidesurfaces of said first and second films through openings created bypenetration and breaking through the first and second films by suchparticles thereby creating further free volume for said particles toexpand into thereby enhancing liquid absorption rate and creatingfurther free volume for the broken-through particles to expand into whenin contact with the liquid. These broken-through particles are spacedapart from each other to minimize touching of such broken throughparticles. A liquid, such as water or water containing plant nutrientsor other ingredients, including for example pesticides, weed killers,and the like, is introduced from an liquid source into the interior ofthe hollow element to cause such liquid to enter the interior and passthrough openings in the sides of the element and then contact the SAPparticles in the container to collect and store such introduced liquidThen later, the collected and stored liquid is dispensed into the soilas the soil dries and additional liquid is required to compensate forwater loss during drying of the soil.

FIG. 9 is an illustration of a vertical cross section of the abovedescribed watering unit. Watering unit 90 comprises hollow element 91clad with sheath 92 which comprises the unit more specifically describedin FIG. 2. SDAP particles 94 serve to dispense water contained in hollowelement 91 into soil 95.

More specifically, such second underground watering system involves aliquid containing water, that is collected externally of a dispensingunit, introduced into the dispensing unit, and then dispensed into soil,and ultimately to plant roots. The collected water may be provided bycollecting rainfall, from a well, from commercial sources, orcombinations thereof. Collected water may be fed by gravity, pressure,or a combination thereof via a pipe or tube into the watering unit. Thewatering unit comprises a rigid tubular member having an open end and aclosed end. The tubular member may be composed of plastic, metal, wood,or combinations thereof. The tubular member is clad with a SAP particlecontaining sheath. The sheath comprises a container having a first filmjoined with a second film, the first film has an adhesive coated firstside surface located on an inside surface of the container and anopposed second side surface located on an outside surface of thecontainer and the second film has a first side surface located on aninside surface of the container and an opposed second side surfacelocated on an outside surface of the container, the first and secondfilms are sufficiently brittle for SAP particles to penetrate and breakthrough the first and second films, the SAP particles are sufficientlylarge to penetrate and break through both first and second side surfacesof the first and second films whereby the SAP particles and extendthrough both first and second films through openings created bypenetration and breaking through the first and second films by the SAPparticles. Water enters the interior of the tubular member and thenexits through openings located on the exterior walls of the tubularmember whereupon water becomes absorbed and stored by the SAP particlesin the sheath. The SAP particles extend beyond the sheath into the soilso that water may be dispensed into the soil. The dispensing rate is afunction of the water content of the soil. Once in soil, the SAPparticles attract and provide water to plant roots. As the processproceeds, watering becomes more efficient the closer the roots approachthe SAP particles. An optimum or preferred water dispensing rate andusage may be determined by simple trial and error.

The product depicted in FIG. 2, 3, or 4 may also be used as apropagation mat in propagation systems for seeds. As shown in theseFigures, water is introduced in the manner illustrated by such Figuresinto a location where the SAP particles are contacted. Then theparticles collect, store, and dispense water into soil trays or vesselscontaining plant seeds where such seeds become propagated.

The above watering method may also be practiced with a differentwatering unit. Rather than using a clad hollow tubular member havingopenings located on the exterior walls, an incomplete tubular member inthe form of an open rigid plastic half circle or angular member with theSAP containing sheath serving to close the open area of the half circlemay be substituted. The incomplete member has an opening to permit waterintroduction on one end and is closed on the other end. In use, thebottom of the open half circle may be placed on a groove in the soil andthe watering unit covered with soil. Water may then be introduced intothe incomplete member. The water becomes absorbed and collected by theSAP particles and then dispersed into the soil to perform plantwatering. Structural elements may be used with the unit to counter theweight of the soil and provide free volume for the unit and the SAPparticles as needed.

The above watering method may yet also be practiced with a differentwatering unit. Rather than using a clad hollow tubular member havingopenings located on the exterior walls, the container may be insertedinto the interior of the above-mentioned hollow member. The SAPparticles may be contacted with water and such collected and storedwater may be expelled from the tubular member through the open areas orholes in the tubular member and into the soil. The tubular member may becircular, square, rectangular, triangular, or any other geometricalshape. FIG. 10 is an illustration of a vertical cross section of theabove described watering unit using a circular cross section. Wateringunit 100 comprises hollow element 101 clad on its exterior with sheath102 which comprises the unit more specifically described in FIG. 2. Asalso shown in FIG. 9, SAP particles 94 serve to dispense water from thehollow interior of watering unit 100 into soil 95.

As will be understood, the second general underground watering methodembodiment of the present invention functions with use of a differentconcept, i.e., water or a water-containing liquid is introduced into theinterior of a hollow element having openings in the wall from theinterior of the element to the exterior where the introduced waterpasses through the openings, contacts the clad container, and becomesabsorbed by the affixed SAP particles of the container. Such introducedwater may be rainwater, artificial water, such as pressurized water froma utility or a well. The clad hollow element is placed at an undergroundor any other desired location and connected to a water source wherebywater is admitted to and fills, to a desired level, the open area in theinterior of the device. Water may be provided continuously orintermittently. This arrangement would conserve water by providing wateronly when needed, minimize overwatering, avoid harmful surface pooling,and salinity buildup in the soil. When irrigating soil with above groundapplied water, the thus applied water floods and sinks into the ground.Over a period of time, salt from that contained in the water, builds upin the soil. Hence, the underground watering inventions of the presentapplication involve reduce salinity build-up and evaporation losses.

Water may be provided to the various watering elements or units by usingcollected rainwater, well water, artificial, pressurized water from acommercial source, or combinations thereof. The absorbed water issubsequently passed into the soil through the SAP particles whichcontact and absorb the water. Following such absorption, water then isexpelled from the SAP particles at the outside of the device into thesoil to provide watering. The SAP particles collect and store water andthen pass such water into the soil where watering would occur due to thelower water content of the soil.

The rate of water passage through the SAP particles depends somewhatupon the water content of the ground and the presence of plant rootsthat have become attracted to the SAP particles. Conceivably, waterwould be provided on an “as needed” basis. Thus, instead of collectingwater into the product of the prior application via SAP particles, wateris dispensed in the other direction, i.e., from the interior of the newproduct. Thus the respective inventive concepts are different

As noted above, the first method and product embodiment comprises twofilms, with at least one film coated with an adhesive and SAP particlesinterposed between the films. The films are joined together by pressurewith a resultant product having joined films with SAP particles havingpenetrated through at least one, but optionally both films, and held inplace or secured in the opening in the film created by the SAP particlepenetration and break through. In the second method and productembodiment, the SAP particles are required to extend through both filmsto function to collect and expel water. A third method and productembodiment utilizes SAP particle breakthrough on only one side of thetwo joined films. Such third embodiment is suitable for plant ball wrapswhere the SAP particles are directed toward the interior of the plantball. All three require an opening and connection to permit theintroduction of liquid between the films for subsequent dispensing intothe soil.

It should be appreciated that the SAP particles in the container may bearranged to only dispense water in a desired direction or location so asto conserve the amount of water and SAP particles. For example, whenwatering plants or directing root growth, SAP particles may be arrangedto extend from the container into the soil in a direction toward theplant root system.

Only certain surface areas of the watering element device, such as thoseexposed in the direction of where watering is desired, need contain SAPparticles. For example, if corn were to be planted above a buried hollowelement and clad container, only the top half surface of the hollowelement and clad container Also the regions of SAP particles could bespaced apart from each other to conserve water by preferentiallydirecting it toward desired areas in the soil. Of course, suchdirectional placement of SAP particles would be suitable for otherapplications of the product, including plant root ball wraps. Forexample, locating SAP particles only on the side of the plant ball wrapfacing the soil ball would result in directing water to the desired areawhile the non-SAP containing other side would not permit loss of wateron such side. The SAP type, particle size, spacing, and location may bedetermined by trial and error as different soils, degrees of soil watercontent, types and needs of plants, type and composition of the wrap,projected frequency of water filling of the watering element device, andwater capacity of such device all contribute to the desired wateringrequirements of the plant. However, it is pointed out that theabove-mentioned unidirectional or one-way exposure of SAP particles isnot essential because plant roots migrate to the source of water andthus would be attracted to and migrate to SAP particles whereverlocated.

Cladding may be performed by simply wrapping one or more SAP containingfilms around the hollow element and joining the films together in anyconvenient manner such as using an adhesive, pressing together each end,heat bonding, sealing, etc. One or more of the same or different wrapscould be employed for cladding the structural member. The structuralmember should be rigid so as to provide structural integrity forprolonged use. Suitable materials include plastic, metal, wood, etc. Amesh, braided or woven plastic or metal material can be used as thestructural member. Of course, reinforcement members could be used forstructural members not having sufficient rigidity. The clad, wateringelement device is preferably closed at one end and the other endconnected to a water source in a sealed manner. The cladding element maybe either loosely arranged around the hollow structural element ratherthan being secured. Cladding may also be accomplished by the use offasteners, adhesives or the like.

There may be an open area between the hollow element and the cladcontainer. The size of such created area created is a function of therespective sizes of the products. Alternatively the film could beadhered or otherwise secured to the structural member. If desired,support elements could be used to maintain the shape of the opening,perhaps at one or both ends and mid-locations.

As set forth above, the invention also includes an underground compositewatering element product for collecting, storing, and dispensingwater-containing liquids into soil. The composite product comprises atleast two containers that are a first film joined with a second film,the first film has an adhesive coated first side surface located on aninside surface of each container and an opposed second side surfacelocated on an outside surface of each container and a second film havinga first side surface located on an inside surface of each container andan opposed second side surface located on an outside surface of eachcontainer, the first film being sufficiently brittle for particles ofSAP to penetrate and break through the first film. The first film hasSAP particles of sufficiently large size to penetrate and break throughthe first and second side surfaces of the first film. The particles areadhered to and extend through the first and second side surfaces of thefirst film through an opening created by penetration and breakingthrough the first film by the particles thereby creating further freevolume for the particles to expand into when in contact with thewater-containing liquid. The broken through particles are spaced apartfrom each other to minimize touching of such particles thereby enhancingwater absorption rate and creating further free volume for these brokenthrough particles to expand into when in contact with saidwater-containing liquid. The SAP particles having been broken throughthe first film penetrate the thus created porous covering and extendinto the soil. The containers have a water absorbent member interposedbetween the containers to form a composite product. The undergroundwatering element is connected to a source of water-containing liquid.

The composite watering element has greater strength that a singlecontainer and thus is useful for applications where strength, includingresistance to deformation, is desirable. In addition, the compositeelement obviously has the ability to collect and store greaterquantities of water-containing liquids than a single container. Theseadvantages are especially useful in processes such as erosion control,irrigation, as well as for athletic field and golf course wateringgrazing fields, and other agricultural uses. Depending upon a specificapplication, the element may be connected to a water source such asrainwater or pressurized water or simply absorb and collect water fromthe adjacent soil.

A typical composite underground watering element is illustrated in FIG.7 which is a vertical cross sectional illustration of such element.Water absorbing member 71 is a water absorbent core containing SAPparticles 73 which are packed and sandwiched between elements 74 and 75.Of course other water absorbing materials such as felt, burlap, sponges,or the like may be substituted for SAP particles 73. It is alsocontemplated to embed or otherwise adhere SAP particles 73 within or onsuch water absorbing materials. All common elements in FIG. 7 are thesame as described in FIG. 1. Element 72 is passageway to permit theentry or exit of water from water absorbing member 71. The use of acomposite watering element adds structural strength to the device so asto minimize unwanted deformation in the soil and to preserve thefunction of the composite product. Suitable water absorbing materialsinclude burlap, felt, and SAP materials such as starch containing SAPparticles. In addition, structural support members can be utilized toimprove structural integrity. Such members included honeycombed members,braces, fillers, and the like.

The above-mentioned new products, in addition to providing watering toplants in general, may be advantageously placed near plant roots forirrigation, placed to direct roots away from sewer pipes, placed todirect roots for seedlings, utilized to prevent or minimize soilerosion, especially on slopes, or for other water collecting anddispensing applications.

A method of watering a plant located in soil may utilize theabove-mentioned composite watering element product This methodembodiment comprises placing such composite product as an undergroundwatering element in soil at a location below a plant and then providinga water-containing liquid to the watering element for collecting,storing, and dispensing the water-containing liquid to the soil toprovide water to said plant. This method is advantageously employed foragricultural, especially for watering golf course greens.

The above watering method is depicted in FIG. 8 which is an illustrationof a vertical cross section of a golf course green containing thecomposite underground watering product of FIG. 7. Golf course green 80contains surface grass 84 and multiple underground layers that are notspecified in FIG. 8. Composite underground watering element 85 has SAPparticles 81 projecting into an adjacent layer of green 80 andconstitutes one of such layers. Water is provided to undergroundwatering element 85 through inlet 83.

Golf course green maintenance is often considered more of an art than ascience. However, there are certain observations to be considered withregard to green watering practice. For example, wet greens provide poorplaying conditions and can lead to infestations of weeds and algae. Onthe other hand, dry greens become hard and do not permit golf balls tohold. Thus a balance between wet and dry greens is desirable. It isbelieved that the underground watering technique of the presentinvention permits the attainment of such desirable balance. Top wateringrequires very close attention to attain such balance and varies fromgreen to green and often involves overwatering. In addition, drainage ofeach green may vary. To address these problems frequent watering insmall amounts becomes necessary. To ensure that top or above groundwatering drains the surface adequately and reaches the grass roots,aeration is routinely employed. Holes created by aeration cause thegreen surface to become uneven and bumpy until grass re-grows over theholes. By watering underground, the problems associated with aerationmay be avoided or minimized and the roots may be watered at a desirabledepth, typically at about 2 to 10 inches in depth, depending upon thetype of grass. In addition, potentially harmful green overwatering maybe prevented. As may be seen, the present underground watering inventiondoes not require above ground watering and thus avoids problemsassociated with above ground watering.

As known in the art, golf course greens are constructed with the use ofmultiple underground layers. In the instance of the present invention,an underground watering element or layer is placed at a depth of about 4to 8 inches to ensure adequate root watering. Such arrangement isillustrated in FIG. 8. Golf course green 80 is comprised of grass 84which is supported by multiple layers. Composite layer 85 is placed at adesired depth below grass 84, for example 2 to 10 inches. Layer 85 is inthe form of a composite underground watering element such as illustratedin FIG. 7. However, the inclusion of a water absorbing material isoptional. Water is introduced into element 85 through entry member 83where the water becomes subsequently dispensed into the ground throughthe SAP particles and comes into contact with the grass roots. Othersuitable watering elements described in the instant specification, suchas that illustrated in FIG. 2, may be employed in place of thatillustrated in FIG. 7. Obviously the optimum time to place theunderground watering element is when a given athletic field or golfcourse green is constructed. However, existing athletic fields andgreens may be modified by underground evacuations which are then filledwith the element.

When the product of the present invention are used as elements tocontrol or minimize soil erosion, the element may be placed undergroundwith use of any of the above-described irrigation elements and/orplacement techniques. Especially when relatively fine SAP particles areused in the erosion control element, water that would otherwise causesoil erosion is rapidly collected, stored, and later dispensed when thesoil becomes drier. It is important to appropriately locate and securethe erosion control element because erosion is a repetitive event. Theerosion control element may be secured in the manner mentioned above inconnection with the irrigation element or may be secured to a stableunderground element such as a rod, screen, stake, pole, hollow cylinder,cage, etc. or any other stable element.

The method of erosion control generally comprises placing an erosioncontrol element beneath the soil and permitting the element to collectand store water thereby preventing water from causing erosion of thesoil. The erosion control element comprises the composite undergroundelement of FIG. 7 and is not connected to a source of a water-containingliquid. However such element may be connected to an exit element whereincollected and stored liquid containing water may be collected andwithdrawn from said underground watering element rather than beingpermitted to be reabsorbed into the soil.

As mentioned above, another method of erosion control involves placingan erosion control blanket on ground where erosion is desired to bereduced. The blanket comprises a watering element and a seeding matdisposed above such element. This method comprises placing the blanketon the ground whereby watering element of the blanket collects, stores,and dispenses water to the seeding mat to assist the seeds to matureinto a plant, such as grass or shrubs, and then to assist further healthof the plants. The growth and subsequent health of the plant serves toreduce undesirable erosion of the ground.

The composite watering element of FIG. 7, in mat form, constitutes asuitable watering element for a portion of the erosion control blanket,although the water dispensing elements of FIGS. 1 and 2 could also beutilized. Seeding mats are known in the art and any type could beutilized in this embodiment. A typical seeding mat that is suitable foruse in the present invention is commercially available from AmericanExcelsior Company, Arlington Tex. This mat is sold for erosion controlpurposes and comprises a fibrous mat having seeds attached to fibers. Itis also possible to form an erosion control blanket having multiplelayers of the watering element and the seeding mat.

The products of the present invention may also be used for horticulturalapplications involving water collection, storage, and dispensing fortrees or other plants contained within wrapped or unwrapped ballslocated in or above the ground. Such products may also be used inconnection with plant root direction control processes. The elements andplacement techniques described in connection with irrigation and erosioncontrol elements are applicable for these applications as well.

The method of the present invention is used to make a product forabsorbing liquids that is useful for, but not limited to, applicationssuch as those described above. In such method, SAP particles are appliedto and coat an adhesive coated side of a first sheet. Optionally,non-woven fabrics or woven fabrics having openings or other materialsthat may be absorbent or non-absorbent may be placed on the SAP particlecoated surface of the first sheet prior to placement of the secondsheet. Such materials may serve to further increase free volume for theSAP particles to expand into when coming in contact with a liquid. It isalso contemplated that these materials may be placed on the adhesivecoated surface prior to application of the SAP particles. In any event,the thus coated first sheet is then placed against or contacted with asecond sheet to join the sheets and then pressure is applied to thejoined sheets to further enhance joining (when the steps of placing andpressing are performed separately) and to cause the SAP particles tobreak through at least the surface of one of the sheets thereby creatingfree volume for the SAP particles to expand when in contact with aliquid. The steps of joining the sheets and breaking through the surfaceof at least one of the sheets with the SAP particles may be performedseparately or concurrently.

Superabsorbent polymeric powders suitable for use in the presentinvention include, but are not limited to, a wide variety of anionic,cationic, and nonionic materials. Suitable polymers includepolyacrylamides, polyvinyl alcohols, ethylene maleic anhydridecopolymer, polyvinylethers, polyacrylic acids, polyvinylpyrrolidones,polyvinylmorpholines, polyamines, polyethyleneimines, polyquaternaryammoniums, natural based polysaccharide polymers such as carboxymethylcelluloses, carboxymethyl starches, hydroxypropyl celluloses, algins,alginates, carrageenans, acrylic grafted starches, acrylic graftedcelluloses, chitin, chitosan, and synthetic polypeptides such aspolyaspartic acid, polyglutamic acid, polyasparagins, polyglutamines,polylysines, and polyarginines, as well as the salts, copolymers, andmixtures of any of the foregoing polymers. Anionic polyacrylamidepolymers are an example of a suitable material. These particles havesharp edges thereby facilitating the ability of the particles to breaktrough the surface of the sheet(s) during the pressing step of thepresent invention.

SAP particles, powders, films, or chips of starch-containingcompositions are also suitable for use in the present invention despitethe fact that such compositions are not generally strong enough to breakthrough the top and bottom sheets of the product. When pressure isapplied perpendicularly to the sheets, starch-containing SAP particlestypically become crushed into a finer powder rather than breakingthrough at least one of the sheets. Despite such lack of strength,starch-containing SAP products may be used in combination with strongerparticulate SAP products such as polyacrylates and polyacrylamides andnon-SAP particles such as sand, rocks, metals, wood, and the like.Suitable starch-containing SAP products are sold under the trade name“Zeba” by ATI, Beaverton, Oreg. U.S. Pat. Nos. 3,425,791; 3,661,815;3,981,100; 3,997,484; 4,134,853; and 4,194,998 are illustrative, but notlimiting, of such starch-containing compositions. Many of such productsare naturally occurring. The second and third of the patents listedabove report water absorption up to 1000 times the weight of thecomposition. Such absorption capacity exceeds that of other typical SAPcompositions such as polyacrylate and polyacrylamide compositions.

In the context of this invention, SAP particles having an average sizefrom about 100 about 500 microns are typically used. The particle sizeis selected to be sufficiently large to penetrate and break the surfaceof one or both sheets when pressure is applied to the sheets and tomaintain a sufficient distance or separation between the respectiveinner surfaces of the container pouch and thereby create and maintainsufficient free volume within the container to permit the neededexpansion of SAP particles upon contact with a liquid.

With the above-enumerated SAP particle size considerations in mind, itis possible to further enhance the performance of the present inventionby utilizing a mixture of fine and coarse SAP powders within thecontainer. As mentioned above, the relatively coarse SAP particleshaving a size ranging from about 100 to 500 microns serve to maintainsufficient distance or separation between the respective inner surfacesof the container pouch to maintain sufficient free volume within thecontainer to permit the needed expansion of the SAP upon contact withliquid. On the other hand, the additional presence of relatively fineSAP particles on the order of from about 20 to about 100 microns servesto enhance the speed of liquid absorption. Thus the mixture of coarseand fine SAP particles permits rapid liquid absorption but yet furthercreates and maintains the necessary free volume in the product to permitSAP powder expansion.

At least one sheet may be a plastic, such as polyvinyl chloride (PVC),or a copolymers of PVC and vinyl acetate or ethylene vinyl acetateprovided that the sheets are sufficiently brittle to permit penetrationand breaking by the SAP particles during the pressing step. In general,plastics containing plasticizers in amounts that impede breakage are notused for both sheets in the invention. Water-soluble plastic sheets arenot typically used as the integrity of the container could becompromised. However, for short term applications or where containerintegrity is not necessary, water-soluble plastics could be used.Cellulosic sheets, such as paper, and metallic foils are alsocontemplated for some applications. The sheet or sheets intended to bebroken typically have a thickness ranging from about 0.05 mils to about0.5 mils Provided that at least one of the sheets meets the requirementsof the invention, the other sheet may be selected from materials that donot meet such requirements.

One or both of the sheets may be coated with an adhesive either prior toor applied, such as by spraying, during the process. Typically the firstor lower sheet is coated with an adhesive although the SAP particlescould be placed on a sheet having no adhesive and the a second sheethaving an adhesive could be placed over and pressed against the firstsheet to adhere the sheets and thereby form the container.

For example, U.S. Pat. Nos. 5,662,758; 5,871,607; and 6,194,062 disclosesheets or films having pressure sensitive coatings protected frominadvertent adherence. Sheets of this type, although certainly notessential to the practice of the present invention, would beadvantageous to the practice of the invention from a sheet handlingaspect if coils of sheet were to be used as a starting material. In anyevent, the sheets disclosed in the above-mentioned patents are suitablefor use in the present invention for one or both of the sheets. Suchsuitability is because these sheets are sufficiently tacky to initiallyadhere the SAP particles to the first sheet and be sufficiently weak topermit the so-adhered particles to break through the surface of thesheet during the pressing step. It is contemplated that solid polymericadhesives such as acrylic (poly isooctyl acrylate), styrenic (styrenecopolymers), and elastomeric (urethane type) may be used in the presentinvention. Typical of these types of solid adhesives are Loctite'sContact Adhesive 30537 and Adchem's adhesive transfer tape Type 1666 (2mils).

To maximize both the rapidness of liquid absorption and overallabsorption properties of the product of the invention, it is necessaryto provide for sufficient free volume surrounding the adhered SAPparticles to permit expansion of such particles when making contact witha liquid. By spacing-apart individual particles during application tothe adhesive coated surface of one of the sheets, free volume is createdalong the sides of the particles and sideways expansion facilitated.Should the particles be placed together or very close together, sidewaysexpansion would be inhibited. The amount of free volume is furtherimproved by causing SAP particles to break through the surfaces of bothsheets thereby additionally permitting additional expansion of theparticle in direction(s) perpendicular to sideways expansion when placedin contact with a liquid.

The process of the present invention may be used to cause openings orholes to be formed through either or both of the sheets by applyingpressure to cause the SAP particles to break through the surface of thesheets. Should a product having such holes on only one sheet is desired,one of the sheets should be selected to be resistant to forming a holewhen the pressure step is conducted. Such result may be achieved byusing a sheet material that is resistant to breakage and/or is thickerthan the particle and thus will not be fully penetrated upon pressing.Such “one-sided” product may be desired for use in applications leakageof absorbed liquid is undesirable, such as in a portion of a diaper coreor a wipe. Of course, a “two-sided” product, i.e., one having holesformed on the surface of both sheets, is desirable for many applicationswhen liquid absorption is desired to be maximized and when subsequentdispensing of the absorbed and collected liquid is desired.

It is advantageous to apply or place the SAP particles on the adhesivecoated surface by sprinkling or otherwise arranging the particles in amanner whereby substantial touching of the applied particles isminimized Application of the SAP particles may be performed in one ormore steps. Spacing the SAP particles apart serves to maximize freevolume on a sideways direction for the particles. Simply sprinkling theparticles on the adhesive coated surface of the sheet is an effectiveapplication technique as no particular pattern is required although itis desirable to uniformly coat the sheet with particles. The amount ofparticles place on the adhesive coated surface is dependent upon thedesired amount of liquid absorption.

Conventional methods useful for applying SAP particles in theabove-described spaced apart manner include curtain coating, spraying,electrostatic spraying such as by Corona discharge, roll coating, andother well-known techniques.

The first and second sheets may be joined by simply placing orcontacting the sheets together thereby utilizing the adhesive to causejoining. It is contemplated using sheets having an adhesive coated onthe surface of both sheets and then contacting both sheets at suchadhesive coated surfaces. Such embodiment serves to enhance the joiningstep of the process and further enhances subsequent securing of the SAPparticles following the pressing and break through step. Furtherenhancement of the joining of the respective sheets is obtained throughthe application of pressure to at least one of the sheets. The steps ofplacing and pressing may be conducted in sequence or concurrently.Enhancing joining of the sheets and further sealing the container may beachieved by leaving a border on the sheet having the applied SAPparticles and then pressing the two sheets together.

Pressure may conveniently be applied by passage of the sheets through aroll nip, rolling either or both surfaces of the joined sheetsseparately or at the same time, through application of pressure by aplate or the like. The process of the present invention may be practicedas a batch process or continuously. If practiced continuously it ispreferred to pass webs of the respective sheets through a roll nipthereby combining the steps of joining the sheets and pressing thejoined sheets. The rolls may be coated with a hard rubber surface orcomprise wood, metal or any other suitable material

The absorbent product of the invention may conveniently be formed byjoining the edges, continuously or intermittently, of at least twosheets to form a pouch-like shape. Although openings may be created atappropriate locations on the surface following assembly of thecontainer, it may be more convenient to create such openings prior tojoining the films. Of course, if the embodiment involving forming holesby pressing a film against SAP particles is utilized, the aspect ofpreforming holes is not necessary, although an enhanced product could bemade by using a sheet having precut or later formed holes and thenforming further holes through the application of pressure against theSAP particles. Such enhancement would permit additional water contactwith the sides of the SAP particles.

The absorbent product of the invention may optionally include openingsat either or both of the sheet surfaces to permit liquid entry. Suchopenings may be sized to permit liquid entry. Typical openingconfigurations include, but are not limited to slits, holes of variousshapes, meshes, etc.

It is contemplated that a pack or series of the absorbent product of thepresent invention may be used to increase the overall or total capacityto absorb liquids. Should the absorbed liquid be desired to be preventedfrom subsequently exiting from the pack, the outer surface of the packcan be formed from a liquid impervious material. The pack or a singleelement could have absorbent and shock reducing material, such as cottonfluff, absorbent woven and non-woven fibers, etc, adjacent one or bothsides of the container. Such arrangement would be suitable for diapers,wipes, feminine hygiene products and similar absorbent products.

When the absorbent product of the present invention is used as anabsorbent core for products, such as a diaper, it is preferred to placethe openings on only one surface of the container; i.e., the surfacefacing the infant. Of course the surface away from the infant would nothave openings to prevent outflow of the liquid urine to undesiredlocations.

A product of the present invention and additional embodiments areillustrated by FIG. 1. This Figure is an illustration of a verticalcross section of the product taken along a longitudinal axis. Sheets 1and 2 are joined together at locations 12 and 13 to form absorbentproduct container 3 which contains SAP particles 4, 5, and 6 whichextend through sheets 1 and 2 to create openings through which liquidsmay enter and exit container 3. Optionally, particles 4, 5, and 6 may benon-SAP particles. In another product embodiment, instead of creatingopenings with the use of particles, preformed hole openings 7, 8, and 9are utilized to permit entry and exit of liquids to container 3. Asillustrated, particles 4, 5, and 6, if comprising SAP particles, arefree to expand upon contact with water or another liquid such as urine,at upper, lower, and side portions thereof because of the free volumecreated by spacing apart particles 4, 5, and 6. Moreover, additional SAPmaterial 10 and 11 (in the form of particles or powder, films, sheets,chips, and the like) may be optionally placed in open areas betweenparticles 4, 5, and 6. The additional SAP material should be of asmaller size than the height of particles 4, 5, and 6 so as to causepenetration and breakage of the sheets only by particles 4, 5, and 6.The additional SAP material may be the same or different compositionthan the larger SAP particles. Smaller SAP particles of the same type asthe larger particles would have the advantage of more rapid liquidabsorption rates. Incorporating a different, second SAP material havinginsufficient strength to penetrate sheets 1 and 2 with strongerparticles 4, 5, and 6 permits the use of weaker, more highly liquidabsorbent SAP products. Thus, the use of the aforementionedstarch-containing SAP material is possible despite the weakness of suchvery high liquid absorbency products when in combination with strongerSAP particles. In addition, the rate of liquid absorption ofstarch-containing SAP materials may be enhanced by using large surfacearea materials, such as fine powders, chips, films, etc. In suchcombination of SAP materials, the larger, stronger particles serve tocreate openings in the absorbent container through which liquids, suchas water or urine, enter the area between the sheets and become absorbedand stored by the SAP material having larger absorption and storagecapacity.

Combinational products of the nature described in the precedingparagraph are beneficial for use as cores for absorbent products such asdiapers and wipes because equivalent liquid absorbance and storagecapacity would be obtained with use of less total SAP weight than ifonly the stronger SAP product were used. Clearly the use of theabove-described combination of SAP products would also have exhibitadvantages when used in irrigation, erosion control, plant watering,root direction control, and similar applications. For such applications,the ability of the starch-containing SAP product to collect and storevery high amounts of water and nutrients, on the order of at least about1000 to about 5000 times the weight of the SAP product is verydesirable. In addition, starch-containing SAP products are known to beable to easily dispense water to plant roots. In the case of theabove-described combinational product, water would pass into theinterior of the container via the SAP particles that extend out,desirably through the surface of the top and bottom sheets, of thecontainer and then pass into the starch-containing SAP product wheresuch water would be collected and stored for subsequent dispersion toplant root systems. Dispensing, like collecting, would occur throughpassage through the extending SAP particles. Such system would have alarger storage capacity, and hence higher efficiency, than if onlyparticles from the extending SAP product were used.

In making the product described in the preceding paragraph, thegenerally described process would be followed with the second SAPproduct either applied as a mixture with the larger first product orapplied to the first sheet separately before or after application of thefirst SAP product. Separate application would permit more accuratespacing of the first SAP product and is thus preferred.

Three additional product embodiments are also included in the presentinvention.

The first embodiment comprises a pouch-like container formed by joiningtwo sheets together. The use of an adhesive coating on one or bothsheets and pressing the sheets together is a convenient mode of joiningthe sheets. Prior to joining the sheets superabsorbent material,including starch-containing SAP material in the form of a powder, afoil, a sheet, and like is placed against one of the sheets and thuswill become contained following joining of the sheets. One or both ofthe sheets contain openings created by non-superabsorbent particles suchas comprising sand, metals, ceramics, wood, rock, hard, and like strong,hard plastics, and other strong, hard materials capable of penetratingthrough one or more of the sheets and forming an opening upon pressingthe sheets.

The second product embodiment is the same as the first embodiment exceptthat preformed openings are utilized in at least one of the sheetsrather that than non-SAP particles.

The third embodiment comprises a combination of the first and secondembodiments and has openings in at least one of the sheets created bythe non-SAP particles and also has preformed openings.

The above described three product embodiments are especially adapted foruse in long term applications such as irrigation, erosion control, plantball watering, and in plant root system root direction controltechniques. Products for such applications may be in the form ofelongated strips or tubes, circular or other shaped strips or tubes, orany other shapes compatible with the intended application. For example,for irrigation applications a long strip-like container may beconveniently placed underground during ground breaking occurring whenplowing and seeding. For other applications, a hole or trench may becreated, the product inserted therein, and the hole then covered.

The present invention also includes a vessel for holding a plantcomprising a container capable of holding a plant wherein the containerhas a pad located at a bottom potion of the container and is connectedto a source of a water-containing liquid The pad comprises a first filmjoined with a second film. The first film has an adhesive coated firstside surface located on an inside surface of the container and anopposed second side surface located on an outside surface of saidcontainer. The second film has a first side surface located on an insidesurface of the container and an opposed second side surface located onan outside surface of the container. Both the first and second films aresufficiently brittle for SAP particles to penetrate and break throughboth films. The SAP particles are of a sufficiently large size topenetrate and break through the first and second side surfaces of bothfilms and thereby extend through the first and second side surfaces ofboth films through openings created by penetration and breaking throughboth first and second films by the SAP particles. The pad may also beconstructed to obtain SAP particle breakthrough only one of the twofilms, depending upon the desired method of use of the pad. In anyevent, water is introduced into the pad from below the pad to cause thewater to become absorbed and collected by the broken through SAPparticles which extend into the soil and then dispense the stored waterfrom the container to cause watering of plant roots contained in thesoil.

The above vessel may also have the broken through SAP particles extendonly into the soil. This embodiment requires that water be introducedinto an interior portion of the pad because the side opposite to thebroken through SAP particle has no such openings.

The product depicted in FIG. 2 may be used as a pad with a vessel forholding plants to collect, store, and dispense a liquid, such as water,into soil and to water a plant contained in such vessel. FIG. 2 is anillustration of a vertical cross section taken along a longitudinal axisof the pad product shown in combination with a water intake element. Allcommon elements in FIG. 2 are the same as described in FIG. 1. Inaddition, opening 14 is utilized to permit the introduction of waterinto pad 3.

As illustrated in FIG. 3 vessel 30 is adapted to hold soil 31 and plant32. FIG. 3 is an illustration of a vertical cross section taken along alongitudinal axis of a vessel for holding plants in which water isintroduced into the interior of a watering pad or propagation mat. Pad33 may comprise the bottom portion of vessel 30 and water 35 passedthrough an opening of tube member 36 and ultimately into pad 33. Wateris collected, stored, and dispensed into soil 31 by SAP particles 37contained in pad 33 whereby plant 32 is watered.

Rather than use pad 33 as the bottom of vessel 30, as illustrated inFIG. 3, it is also possible to use a vessel having a solid bottom andsimply place pad 41 on the inside bottom of vessel 30. Such embodimentrequires that water introduction be introduced into water holding tray43 to permit the passage of water from tray 43 into pad 33 through holesor openings 44. Such product is illustrated in FIG. 4 which is anillustration of a vertical cross section taken along a longitudinal axisof a vessel for holding plants shown in combination with a watering pador propagation mat in which water is introduced externally into such pador mat. All common element numbers in FIG. 4 are as described in FIG. 3.

FIG. 5 is an illustration of a horizontal cross section of a wateringcollar to be placed and secured upon a plant root ball, such as a treeroot ball. The plant has roots and is contained in a soil ball (notillustrated). The root ball is wrapped in a porous covering, such asburlap, and has a watering collar secured thereto at a desired location.The watering collar comprises a first film joined with a second film.The first film has an adhesive coated first side surface located on aninside surface of the water collar container and an opposed second sidesurface located on an outside surface of the container. The second filmhas a first side surface located on an inside surface of the containerand an opposed second side surface located on an outside surface of thecontainer. The first film is sufficiently brittle for the SAP particlesto penetrate and break through the first film which has SAP particles ofsufficiently large size to penetrate and break through the first andsecond side surfaces of the first film. These particles are adhered toand extend through the first and second side surfaces of the first filmthrough openings created by penetration and breaking through the firstfilm by the particles thereby creating further free volume for theparticles to expand into when in contact with water. The broken-throughparticles are spaced apart from each other to minimize touching of thebroken through particles thereby enhancing water absorption rate andcreating further free volume for the broken through particles to expandinto when in contact with water. The SAP particles do not break throughthe second film in the embodiment illustrated in FIG. 5 as such film ismade from a less brittle plastic, such as that having an appreciableplasticizer content. In any event, the SAP particles having been brokenthrough the first film then penetrate into the porous covering andextend into the soil. The watering collar has as an opening connectionto a source of liquid whereby the water may be introduced into an openarea in the water collar, collected and stored by the SAP particles, anddispensed into the soil of the plant root ball.

More specifically, water collar 50 is formed into a circular shape to beable to surround a plant root ball in the open area indicated by element51. Water collar 50 may be placed upon and secured to a burlap tree ballwrap. Securing may be by fasteners such as clips, ties, straight rodelements placed below the collar which extend into the soil of the ball,adhesives, etc. It is contemplated that the collar may be a straightshape which is wrapped around the ball and then the ends joined to forma circular shape. The ends may be joined by tying, fastening with clips,clamps, Velcro or other types of adhesive fasteners, etc. Sucharrangement permits custom fitting to a given plant root ball and alsopermits reuse of the collar. Collar 50 has SAP particles 52 brokenthrough first film 53 and exposed to water that is introduced from inlet54 into the space between first film 53 and second film 55. Fasteningrods 56 serve to secure watering collar 50 to the plant root ball.

A second water collar embodiment is illustrated in FIG. 6 which is anillustration of another horizontal cross section watering collarembodiment to be placed and secured to a plant root ball. All commonelement numbers in FIG. 6 are discussed in FIG. 5. In this embodiment,SAP particles 52 extend through both first films 53 and second film 55.Covering film 67 surrounds first film 53 and second film 55 and createsa space (not shown) between film 55 and covering film 67. Like FIG. 5,water is introduced from inlet 54. However, such water is collected inopen space 58 where water is absorbed and collected by SAP particles 52for dispensing into the soil of the plant root ball. Covering film 67surrounds and is connected to first film 53 and second film 55 byattachment with fastening rods 56. Alternatively, films 53, 55, and 67may be joined together, for example by an adhesive, at the ends andsides of the films. The amount of opening can be controlled by therelative sizes or dimensions of the films. For example, the larger film67, the larger the opening between films 55 and 57. The same holds truefor the size of the opening between films 53 and 55 in this embodimentillustrated in FIG. 6 and in the embodiments of FIGS. 1-5.

Once a plant root ball has been placed/transplanted into a pre-madeopening created in the soil that is sized to receive the root ball, itmay be desirable to provide water to the root ball. The transplantedroot ball may or not be wrapped with burlap, may or may not have awatering collar of the type described in the present application. In anyevent, the watering method comprises placing a watering elementcontaining SAP, such as that illustrated by FIGS. 2 and 7, into theunderground opening suitable for holding a plant root ball, and thenplacing the root ball into the opening, and then providing a liquidcontaining water into the watering element where the provided liquidpasses into the soil from SAP contained in the watering element wherebythe roots of the plant are watered. The watering element mayadvantageously be in the form of a mat. The mat may be sized to fill thebottom of the opening or sized to be larger than the opening. When sizedto be larger than the opening, the mat covers the bottom and sidewall,portions of the opening thereby providing enhanced watering capability.

The invention may be further understood by reference to the followingExamples.

Example 1

SAP particles having an average size of about 300 microns are applied ina spaced apart pattern to a first PVC sheet having a solid adhesivecoating to cause the particles to become adhered to the sheet. A secondPVC sheet is then pressed against the coated first sheet with use of ametal plate to cause the sheets to become joined together and theadhered SAP particles to penetrate and break through the surfaces ofboth sheets. The resultant pouch-like container product is characterizedas having good liquid absorption properties when placed in contact witha liquid.

Example 2

Example 1 is repeated except that the first sheet is made frompolyethylene. The resultant product has SAP particles that are onlybreak through the surface of the second PVC sheet. The resultantpouch-like container product is characterized as having good liquidabsorption properties when placed in contact with a liquid.

Example 3

Example 1 is repeated except that a mixture of coarse and fine SAPparticles is applied to the first sheet. The coarse particles have anaverage particle size of about 300 microns and the fine particles havean average particle size of about 40 microns. During the pressing steponly the coarse particles penetrate and break through the surface of thetwo sheets. The resultant pouch-like container product is characterizedas having good liquid absorption properties when placed in contact witha liquid.

Example 4

Example 1 is repeated except that a powder of starch containing SAP isalso applied to the first sheet in addition to the SAP particles havingan average particle size of about 300 microns. Upon pressing the sheetstogether only the SAP particles having an average particle size of about300 microns break through the surface of both sheets. The resultantpouch-like container product is characterized as having good liquidabsorption properties when placed in contact with a liquid.

Example 5

Example 4 is repeated except that non-SAP particles comprised of sandand having an average particle size of about 500 microns are substitutedfor the SAP particles and small openings or holes are provided throughboth sheets. The sheets are pressed and joined together and the sandparticles break through the surfaces of both sheets. The resultantpouch-like container product is characterized as having satisfactoryliquid properties when placed in contact with a liquid.

Example 6

A tree seedling is planted in the ground and permitted to grow to aboutthree feet in height. The seedling and surrounding soil is thenextracted in the form of a tree root ball. During extraction, a numberof fine root ends of the tree become severed because such fine rootsextended beyond the severed area. As a result of forming the tree rootball, the root system is damaged to the extent that the tree may becomestunted or even die. The damaged tree root ball is wrapped in burlap andplaced on the ground and stored at a nursery awaiting sale. A wateringcollar, such as depicted in FIG. 6, is placed around the wrap at alocation in the ball corresponding to the tree roots and then secured inplace with by fastening both ends of the collar together with a clamp.Water is then introduced into the interior of the watering collarthrough an on-off connection to a hose, the hose removed, and theconnection to the collar is closed. The water in the interior isabsorbed, collected, and stored by the SAP particles and subsequently isdispensed, by SAP contained in the collar, into the soil of the treeroot ball and the tree roots are watered. Once the water contained inthe interior is exhausted or somewhat depleted, additional water isadded by the same procedure. The amount of water dispensed into the soilvaries with the water content of the soil, with more water beingdispensed as the soil dries. The tree roots grow to a normal statefollowing dispensing and stunting is minimized and death avoided. Thetree ball is then transplanted into a desired location in the ground.

Example 7

Example 6 is repeated except that the tree root ball does not have acompromised root system. Again watering serves to preserve the health ofthe tree roots during storage while it awaits transplantation.

Example 8

The watering element illustrated in FIG. 2 is placed in an openingcreated beneath the soil and then is covered by soil. The wateringelement is connected to a source of water. The source is a rectangularplastic box with an open top located above ground. Corn plant seeds areplaced in the covered soil and corn is grown from such seeds. Rainoccurs and rainwater is collected in the box and is fed under theinfluence of gravity into the watering element where the water iscollected and passes from SAP particles contained in the wateringelement into the soil and provides water to the roots of the corn. Thiswatering procedure is repeated as rain occurs. Water from another sourceis added periodically during periods of light or no rainfall.

Example 9

Example 8 is repeated except that the watering element illustrated inFIG. 7 is used.

The invention claimed is:
 1. A vessel for holding a plant comprisinginterior, bottom, and side portions, and having a watering padcontaining particles of superabsorbent polymeric powder and located atsaid bottom potion of said vessel, said pad connected to a source of awater-containing liquid, said pad comprising a first film joined with asecond film, said first film having an adhesive coated first sidesurface located on an inside surface of said pad and an opposed secondside surface located on an outside surface of said pad and said secondfilm having a first side surface located on an inside surface of saidpad and an opposed second side surface located on an outside surface ofsaid pad, said first and second films being sufficiently brittle forsaid particles of superabsorbent polymeric powder to penetrate and breakthrough said first and second films, said particles of superabsorbentpolymeric powder of sufficiently large size to penetrate and breakthrough said first and second side surfaces of said first and secondfilms, said particles extending through said first and second sidesurfaces of said first and second films through openings created bypenetration and breaking through said first and second films by saidparticles thereby creating free volume for said particles to expand intoto cause enhanced liquid absorption rate when in contact with saidliquid, said broken through particles spaced apart from each other tominimize touching of said broken through particles and directed intosaid interior of said vessel.
 2. The vessel of claim 1, wherein saidvessel includes a passage having an open end for introducing saidwater-containing liquid from said open end to said pad.
 3. The vessel ofclaim 2, wherein said passage extends from a top portion of said vessel,along a side wall of said vessel, and to said pad.